| Official Name: | Sirdar-e Pain |
| Native Name: | سيردرپائين |
| Settlement Type: | village |
| Pushpin Map: | Iran |
| Mapsize: | 150px |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Name1: | Lorestan |
| Subdivision Type2: | County |
| Subdivision Name2: | Kuhdasht |
| Subdivision Type3: | Bakhsh |
| Subdivision Name3: | Central |
| Subdivision Type4: | Rural District |
| Subdivision Name4: | Kuhdasht-e Shomali |
| Population As Of: | 2006 |
| Population Total: | 64 |
| Population Density Km2: | auto |
| Timezone: | IRST |
| Utc Offset: | +3:30 |
| Timezone Dst: | IRDT |
| Utc Offset Dst: | +4:30 |
| Coordinates: | 33.7228°N 47.5481°W |
Sirdar-e Pain (Persian: سيردرپائين, also Romanized as Sīrdar-e Pā’īn; also known as Sīrdar) is a village in Kuhdasht-e Shomali Rural District, in the Central District of Kuhdasht County, Lorestan Province, Iran. At the 2006 census, its population was 64, in 10 families.